20p a tube - not bad!

Indeed a bargain for any tibe, not least the proper German ones! Nice that they are the older /23 ones rather than /535 marked.

@Slyspark: As soon as I was told it was 5 quid I was like 'brilliant go ahead' especially for these quality tubes @Beta 5: Proper German OSRAM tubes last a crazy long life from what I've heard and is there a colour tint difference between 535 and /23 marked?

Yeah as far as I know these German Osram's did last very well! No /23 and /535 are the same, /23 is just Osram speak for the generic 3 digit colour code of 535, just the same as Philips and GE tubes marked /35 (and later /35-535) and Sylvania tubes marked 135, all Halophosphor 3500K white. A tube without the 3 digit code and instead a company specific colour code like these is generally older though

This vintage of Osram tube will run a decade in daily use and still look like they've had little use

We had some of these Osram tubes at work, they lasted a very long time, even when looking near EOL they kept on going!